Noise Knowledge
Noise can be proven with numbers — Geonoise measures with instruments calibrated by an ISO/IEC 17025 accredited laboratory, usable as legal evidence.
Noise from a neighbour, a venue, or a factory isn't just annoying — it disrupts sleep, raises stress, erodes concentration, and harms long-term physical and mental health. Many people feel that no one will listen or that they can't prove the problem.
The good news: noise can be proven with numbers. A correct measurement turns a feeling of being disturbed into hard, usable evidence.
Thailand sets the nuisance-noise limit at 10 dBA above the background level, under National Environment Board Notification No. 29 (B.E. 2550). Measurement must use an IEC 61672-1 Class 1 sound level meter and follow the Pollution Control Department's method (B.E. 2565).
Results only count as evidence when taken with calibrated equipment, at the right location and time (where the affected person actually lives), and assessed by an independent expert. A phone app or uncalibrated meter cannot be used in a legal process.
Geonoise measures with instruments calibrated by an ISO/IEC 17025 accredited laboratory, and evidence-grade reports are issued by the ALT laboratory under its ISO/IEC 17025 accreditation. If you're about to file a complaint or pursue a case, we make your data strong enough to rely on.
Full knowledge content (measurement & decibels, noise types and sources, law and standards, health effects) rolls out in Phase 3 of the plan.
Knowledge topics
10 dB or 10 dB(A)? The difference that decides whether your noise problem gets solved
What is the difference between 10 dB and 10 dB(A), and why a guarantee of “10 dB of noise reduction” can leave your noise problem exactly where it was.
What is STC (Sound Transmission Class) and how is it tested?
STC, the Sound Transmission Class, is a single number that says how well a wall, floor, door or window blocks airborne sound: the higher the STC, the less sound gets through. It is measured in a laboratory to ASTM E90 and rated to ASTM E413. On site, in a finished building, the equivalent values are ASTC (ASTM E336) or DnT,w (ISO 16283-1), and they are normally 5–10 points lower than the laboratory figure. This article explains what the number means, how the test is done, what rating you need, and why the laboratory and field values differ.
What Is a Decibel? The dB Scale, Adding Levels and a Table
Everyone has heard of the decibel and most people use it wrongly, because it is not a linear scale: 60 dB is not twice as loud as 30 dB, and two machines at 80 dB do not add up to 160 dB. This page explains what a decibel is, why it is logarithmic, the 3 dB and 10 dB rules worth memorising, how to add decibels, what dBA means, and a table of everyday levels set against the Thai legal limits.
Noise Barriers: How They Work, Types and Real Results
A noise barrier is the most-requested mitigation for factories, expressways, construction sites and car parks in Thailand, and the one most often built wrong. This page explains how a barrier reduces noise, how many decibels it realistically delivers, how high and long it has to be, which material suits which job, when a barrier will not help at all, and why the design should be calculated before any money is spent. Geonoise designs and verifies barriers; it does not sell or install them.
Online Noise Monitoring: Components, Uses and Requirements
An online noise monitoring system is a permanent or semi-permanent station that logs sound levels around the clock, sends them to a web dashboard and raises an alert when a threshold is exceeded. It is increasingly used on construction sites next to communities, in factories with EIA conditions, at entertainment venues and on rail projects. This page explains what a system consists of, how it differs from an attended survey, when it is required, what makes its data defensible, and whether to rent, buy or take it as a service.
Soundscape: How People Perceive Sound, Not Just Decibels
A soundscape is the acoustic environment as perceived and understood by people in the context of a place — the definition in ISO 12913-1. It differs from noise control in the question it asks: not "how many decibels?" but "does what you hear fit this place?". A park with a fountain at 60 dBA can feel calm while a room with air-conditioning at 45 dBA feels irritating. This page explains the principle, the ISO 12913 assessment method, where it applies in urban design, buildings and development projects, and where it stops and legal noise measurement begins.
STI and STIPA: how speech intelligibility is measured for PA, voice alarm and PAGA systems
STI, the Speech Transmission Index, is a number from 0 to 1 that says how well speech from a loudspeaker or a talker will be understood at a listener's position. It is defined in IEC 60268-16 and is the metric that voice alarm, voice evacuation and PAGA specifications use to decide whether a system passes. STIPA is the short form of the measurement, quick enough to test a public address system position by position. This article explains what the number means, how it is measured on site, and what values specifications ask for.
Noise Measurement: dB, dBA, Leq and Sound Level Meters
A noise measurement is only as good as the choices behind it: which decibel scale, which time weighting, which metric, which instrument class, where the microphone stood and for how long. This page explains the terms you will meet in a Thai measurement report or regulation — dB, dBA, dBC, Fast/Slow, Leq, Lmax, L90, SEL, Lden, dose and TWA — and the field practice that makes a result defensible.
Noise Law and Standards
A summary of the international frameworks and the Thai law used to design, assess and enforce acoustics — from community and environmental noise to occupational health, buildings and specialist rooms. The focus is on what you actually have to do, and what you have to document, for a project to be both compliant and traceable.
Effects of Noise on Health and the Environment
Noise acts on people in two ways: directly on the ear, when exposure is high enough to damage hearing, and indirectly through sleep, concentration, stress and the cardiovascular system at levels far below that. It also changes how animals communicate and use space. This page sets out the thresholds that matter, the warning signs, and the metric and response that fit each situation.
Noise Control: Source, Path and Receiver
Noise control follows one logic: reduce the source, cut the path, protect the receiver, in that order of preference. This page explains the physical tools — mass, decoupling, damping, sealing, absorption, isolation, barriers — where each one works and where it does not, and how a project goes from diagnosis to a verified result. Geonoise designs and verifies these measures; it does not sell them.
Noise Monitoring: Surveys, Stations and Reporting
Monitoring makes the problem visible: not only the average level but the events, the time of day they happen and the trend after something is changed. This page covers how a monitoring programme is designed, the instruments, the quality controls that make the data defensible, and how the result is reported to a regulator, a client or a community.
Thai Noise Law: Limits, Nuisance, Factories and Workplaces
Every Thai law that governs noise and vibration on one page: the environmental framework act and its general noise limits, the nuisance provisions of the Public Health Act, the Factory Act, the workplace regulation under the Labour Protection Act, the Criminal Code, and the Bangkok rules for entertainment venues, with the numerical limits and penalties. Compiled from Pollution Control Department publications; figures and instruments are revised from time to time, so check the version in force before relying on them.
FAQ
What is Thailand's nuisance-noise limit?
The disturbance level should not exceed 10 dBA above the background level, under National Environment Board Notification No. 29 (B.E. 2550).
Can a phone app measurement be used as evidence?
No. The law requires a calibrated IEC 61672-1 Class 1 sound level meter and the calculation method set by the Pollution Control Department.
How do I start a noise complaint?
Record the dates, times and nature of the noise, request an independent standards-based measurement, and contact the relevant authority (municipality, PCD, or police). Geonoise can prepare defensible evidence.